pnfs/blocklayout: allocate separate pages for the layoutcommit payload

Instead of overflowing the XDR send buffer with our extent list allocate
pages and pre-encode the layoutupdate payload into them.  We optimistically
allocate a single page use alloc_page and only switch to vmalloc when we
have more extents outstanding.  Currently there is only a single testcase
(xfstests generic/113) which can reproduce large enough extent lists for
this to occur.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Christoph Hellwig 2014-09-10 17:36:30 -07:00 committed by Trond Myklebust
parent d4b18c3e00
commit 34dc93c2fc
3 changed files with 92 additions and 35 deletions

View File

@ -500,21 +500,16 @@ bl_return_range(struct pnfs_layout_hdr *lo,
err = ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end);
}
static void
bl_encode_layoutcommit(struct pnfs_layout_hdr *lo, struct xdr_stream *xdr,
const struct nfs4_layoutcommit_args *arg)
static int
bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
{
dprintk("%s enter\n", __func__);
ext_tree_encode_commit(BLK_LO2EXT(lo), xdr);
return ext_tree_prepare_commit(arg);
}
static void
bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
{
struct pnfs_layout_hdr *lo = NFS_I(lcdata->args.inode)->layout;
dprintk("%s enter\n", __func__);
ext_tree_mark_committed(BLK_LO2EXT(lo), lcdata->res.status);
ext_tree_mark_committed(&lcdata->args, lcdata->res.status);
}
static int
@ -670,7 +665,7 @@ static struct pnfs_layoutdriver_type blocklayout_type = {
.alloc_lseg = bl_alloc_lseg,
.free_lseg = bl_free_lseg,
.return_range = bl_return_range,
.encode_layoutcommit = bl_encode_layoutcommit,
.prepare_layoutcommit = bl_prepare_layoutcommit,
.cleanup_layoutcommit = bl_cleanup_layoutcommit,
.set_layoutdriver = bl_set_layoutdriver,
.alloc_deviceid_node = bl_alloc_deviceid_node,

View File

@ -72,6 +72,9 @@ struct pnfs_block_extent {
unsigned int be_tag;
};
/* on the wire size of the extent */
#define BL_EXTENT_SIZE (7 * sizeof(__be32) + NFS4_DEVICEID4_SIZE)
struct pnfs_block_layout {
struct pnfs_layout_hdr bl_layout;
struct rb_root bl_ext_rw;
@ -129,8 +132,7 @@ int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
sector_t len);
bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
struct pnfs_block_extent *ret, bool rw);
int ext_tree_encode_commit(struct pnfs_block_layout *bl,
struct xdr_stream *xdr);
void ext_tree_mark_committed(struct pnfs_block_layout *bl, int status);
int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg);
void ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status);
#endif /* FS_NFS_NFS4BLOCKLAYOUT_H */

View File

@ -462,32 +462,37 @@ out:
return err;
}
int
ext_tree_encode_commit(struct pnfs_block_layout *bl, struct xdr_stream *xdr)
static void ext_tree_free_commitdata(struct nfs4_layoutcommit_args *arg,
size_t buffer_size)
{
if (arg->layoutupdate_pages != &arg->layoutupdate_page) {
int nr_pages = DIV_ROUND_UP(buffer_size, PAGE_SIZE), i;
for (i = 0; i < nr_pages; i++)
put_page(arg->layoutupdate_pages[i]);
kfree(arg->layoutupdate_pages);
} else {
put_page(arg->layoutupdate_page);
}
}
static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p,
size_t buffer_size, size_t *count)
{
struct pnfs_block_extent *be;
unsigned int count = 0;
__be32 *p, *xdr_start;
int ret = 0;
dprintk("%s enter\n", __func__);
xdr_start = xdr_reserve_space(xdr, 8);
if (!xdr_start)
return -ENOSPC;
spin_lock(&bl->bl_ext_lock);
for (be = ext_tree_first(&bl->bl_ext_rw); be; be = ext_tree_next(be)) {
if (be->be_state != PNFS_BLOCK_INVALID_DATA ||
be->be_tag != EXTENT_WRITTEN)
continue;
p = xdr_reserve_space(xdr, 7 * sizeof(__be32) +
NFS4_DEVICEID4_SIZE);
if (!p) {
printk("%s: out of space for extent list\n", __func__);
(*count)++;
if (*count * BL_EXTENT_SIZE > buffer_size) {
/* keep counting.. */
ret = -ENOSPC;
break;
continue;
}
p = xdr_encode_opaque_fixed(p, be->be_device->deviceid.data,
@ -498,25 +503,80 @@ ext_tree_encode_commit(struct pnfs_block_layout *bl, struct xdr_stream *xdr)
*p++ = cpu_to_be32(PNFS_BLOCK_READWRITE_DATA);
be->be_tag = EXTENT_COMMITTING;
count++;
}
spin_unlock(&bl->bl_ext_lock);
xdr_start[0] = cpu_to_be32((xdr->p - xdr_start - 1) * 4);
xdr_start[1] = cpu_to_be32(count);
dprintk("%s found %i ranges\n", __func__, count);
return ret;
}
void
ext_tree_mark_committed(struct pnfs_block_layout *bl, int status)
int
ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg)
{
struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout);
size_t count = 0, buffer_size = PAGE_SIZE;
__be32 *start_p;
int ret;
dprintk("%s enter\n", __func__);
arg->layoutupdate_page = alloc_page(GFP_NOFS);
if (!arg->layoutupdate_page)
return -ENOMEM;
start_p = page_address(arg->layoutupdate_page);
arg->layoutupdate_pages = &arg->layoutupdate_page;
retry:
ret = ext_tree_encode_commit(bl, start_p + 1, buffer_size, &count);
if (unlikely(ret)) {
ext_tree_free_commitdata(arg, buffer_size);
buffer_size = sizeof(__be32) + BL_EXTENT_SIZE * count;
count = 0;
arg->layoutupdate_pages =
kcalloc(DIV_ROUND_UP(buffer_size, PAGE_SIZE),
sizeof(struct page *), GFP_NOFS);
if (!arg->layoutupdate_pages)
return -ENOMEM;
start_p = __vmalloc(buffer_size, GFP_NOFS, PAGE_KERNEL);
if (!start_p) {
kfree(arg->layoutupdate_pages);
return -ENOMEM;
}
goto retry;
}
*start_p = cpu_to_be32(count);
arg->layoutupdate_len = sizeof(__be32) + BL_EXTENT_SIZE * count;
if (unlikely(arg->layoutupdate_pages != &arg->layoutupdate_page)) {
__be32 *p = start_p;
int i = 0;
for (p = start_p;
p < start_p + arg->layoutupdate_len;
p += PAGE_SIZE) {
arg->layoutupdate_pages[i++] = vmalloc_to_page(p);
}
}
dprintk("%s found %zu ranges\n", __func__, count);
return 0;
}
void
ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status)
{
struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout);
struct rb_root *root = &bl->bl_ext_rw;
struct pnfs_block_extent *be;
dprintk("%s status %d\n", __func__, status);
ext_tree_free_commitdata(arg, arg->layoutupdate_len);
spin_lock(&bl->bl_ext_lock);
for (be = ext_tree_first(root); be; be = ext_tree_next(be)) {
if (be->be_state != PNFS_BLOCK_INVALID_DATA ||